1) Field of the Invention
Embodiments of the present invention relates to the inspection of a workpiece and, more particularly, to systems and methods for providing two-dimensional and three-dimensional information indicative of a workpiece.
2) Description of Related Art
Composite structures are commonly manufactured by progressively building up the structure with a plurality of layers of thin composite tape (or tow) laid one layer upon another. Typically, the operation begins by laying one or more tapes onto a starting template or tool that has a configuration generally corresponding to the desired shape of the article to be produced. A tape placement head of a manufacturing system moves over the surface of the template, guiding the one or more tapes of composite material onto the template. The head usually makes repeated passes over the template in a defined pattern until the composite material is entirely collated, building up successive layers of the composite tape to form the desired workpiece. A compaction roller is typically used for pressing the tape against the workpiece, thereby facilitating adhesion of the successive layers. The workpiece may then be subjected to a curing process (e.g. heating) to further adhere and bond the composite layers. Conventional systems for forming composite structures using successive layers of tape include those systems disclosed, for example, in U.S. Pat. No. 6,799,619 issued to Holmes et al., and U.S. Pat. No. 6,871,684 issued to Engelbart et al.
The measurement accuracy required by the manufacturing specification, which is in turn driven by design requirements, in areas such as ply boundaries, tape edge gaps and overlaps, material wrinkles, and the presence of foreign object debris (FOD), has created a need to make those measurements with a robust automated system. Prior and emerging art, using various machine vision technologies, have provided limited capabilities to meet these requirements. As such, manual visual inspection of composite plies is frequently employed, which may be unreliable, inefficient, and subject to operator error. Namely, the machine must be stopped and the process of laying materials halted until the inspection is complete. During the inspection, the operator verifies the dimensions of any suspect defects and quantifies the number of defects per given unit area. The defects are repaired as needed and laying of the next ply proceeds. Therefore, current visual inspection techniques are insufficient to move into a production environment with systems that require efficient and reliable inspection of the workpiece.
It would therefore be advantageous to provide systems and methods for inspecting a workpiece to increase the reliability and accuracy of the inspection of the workpiece. In addition, it would be advantageous to provide systems and methods to increase the quality of a workpiece, the production rate, and inspection efficiency, as well as reduce the overall cost of the manufacturing and inspection processes.